J/A+A/xxx/xxx ... (J.Schulz, 2002) ================================================================================ Wavelength and Redshift Dependence of Bulge/Disk and Bulge/Total Light Ratios in Galaxies J. Schulz and U. Fritze - v. Alvensleben and K. J. Fricke =2002A&A...xxx..xxxK ================================================================================ ADC_Keywords: Galaxies, evolution of; Galaxies, formation of; Galaxies:fundamental parameters; Galaxies: general; Galaxies: stellar content Abstract: HST has opened the possibility to decompose the surface brightness profiles of galaxies up to significant redshifts and look-back times into ${\rm r^{1/4} -}$ bulge and exponential disk components. This should allow to study the redshift evolution of bulge and disk luminosity contributions and discriminate between the different formation scenarios for these galaxy components currently discussed, i.e. decide if star formation in bulges and disks started at the same time or was delayed in either of the two components. An indispensable prerequisite for the comparison of bulge-to-disk ratios of galaxies at different redshifts is to properly account for cosmological band shift and evolutionary effects. We present evolutionary synthesis models for both components and add their spectra in various proportions to obtain the full range of local galaxies' B-band bulge-to-total light ratios. Bulge star formation is assumed to occur on a short timescale of $10^9$ yr, disk star formation proceeds at a constant rate. We study the evolution of the relative light contributions of both components backward in time and, for a given cosmological model, as a function of redshift. This allows us to see how far back into the past the locally well-established correlation between galaxy morphologies and spectral properties can hold. To cope with the present uncertainty about the formation epochs of bulge and disk components we present models for three scenarios: bulges and disks of equal age, old bulges and delayed disk star formation, and old disks with subsequent bulge star formation. We quantitatively show the wavelength dependence of bulge-to-total ($=$ B/T) light ratios for local galaxies. The different star formation timescales for bulge and disk components lead to B/T ratios that significantly increase from U through I-bands (by factors 4 -- 6 for weak bulge systems $\sim$ Sc) with the rate of increase slightly depending on the relative ages of the two components. The redshift evolution of B/T-ratios in various bands U . . . I is calculated accounting both for cosmological and evolutionary corrections assuming a standard cosmology (${\rm H_0 = 65,~\Omega_0 = 0.1,~\Lambda_0 = 0}$). In particular, for the two scenarios with old bulges and old or younger disks, the redshift evolution of B/T-ratios is dramatic in every band and both for galaxies ending up at ${\rm z \sim 0}$ with low and high B-band B/T light ratios. Our results clearly show that it does not make any sense to compare B/T ratios measured in one and the same band for galaxies at different redshifts without fully accounting for evolutionary and cosmological effects. These, unfortunately, significantly depend on the relative ages of the two components and, hence, on the galaxy formation scenario adopted. We also show that simultaneous decomposition of galaxy profiles in several bands can give direct information about these relative ages and constrain formation scenarios for the different galaxy components. Description: Spectra, colors, luminosities and B/T ratios in various filter-systems as well as cosmological and evolutionary corrections in the cosmology (H_0=65,\Omega_0=0.1,\Lambda_0=0.0) for the 4 components and their related B/T scenarios. The timestep is 4*10^6 years. the UBV filters are from Buser & Kurucz (1978),the RI filter from Bessell (1990) and JHK from Bessel & Brett (1988). Files are sorted in directorys with following naming-convention: scalo = indicates the use of scalo IMF Z1 = 0.0004 Z2 = 0.004 Z3 = 0.008 Z4 = 0.02 Z5 = 0.05 84_84 = scenario with equally old bulge and disk 84_50 = scenario with old bulge and young disk 50_84 = scenario with old disk and young bulge the e- & k-corrections can be found in ek_in_l.dat corresponding to the cosmology with H_0=65 as seen above. Both k-corrections with and without attenuation are included. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe xx . This file colors.dat xx xxx luminosities and colors from the spectra in various filter-systems. multi-block-file galspec.dat xx xxx spectra. multi-block-file plotsgal.dat xx xxx isochrone intrinsic colors. multi-block-file ek_in_l.dat xx xxx e- & k-corrections in luminosities, cosmology with H_0=65 bt.dat xx xxx bulge/total relations in age and redshift for U,V,B,I,H (HST-filters) -------------------------------------------------------------------------------- Byte-by-byte Description of file: ek_in_l.dat (first block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-12 F12.4 --- eu e-correction for Johnson U 13-24 F12.4 --- eb e-correction for Johnson B 25-36 F12.4 --- ev e-correction for Johnson V 37-48 F12.4 --- er e-correction for Johnson R 49-60 F12.4 --- ei e-correction for Johnson I 61-72 F12.4 --- ej e-correction for Johnson J 72-84 F12.4 --- eh e-correction for Johnson H 85-94 F12.4 --- ek e-correction for Johnson K 95-102 F8.2 --- z redshift -------------------------------------------------------------------------------- Byte-by-byte Description of file: ek_in_l_xx.dat (second block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-12 F12.4 --- eku e-correction for Koo u 13-24 F12.4 --- ekb e-correction for Koo j 25-36 F12.4 --- ekv e-correction for Koo f 37-48 F12.4 --- ekr e-correction for Koo n 49-60 F12.4 --- egi e-correction for Thuan & gunn g 61-72 F12.4 --- egj e-correction for Thuan & gunn r 73-80 F8.2 --- z redshift -------------------------------------------------------------------------------- Byte-by-byte Description of file: ek_in_l_xx.dat (third block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-11 F11.4 --- eF160BW e-correction HST F160BW 12-22 F11.4 --- eF170W e-correction HST F170W 23-33 F11.4 --- eF185W e-correction HST F185W 34-44 F11.4 --- eF218W e-correction HST F218W 45-55 F11.4 --- eF255W e-correction HST F255W 56-66 F11.4 --- eF300W e-correction HST F300W <==> U(HDF) 67-77 F11.4 --- eF336W e-correction HST F336W 78-88 F11.4 --- eF380W e-correction HST F380W 89-99 F11.4 --- eF439W e-correction HST F439W 100-110 F11.4 --- eF450W e-correction HST F450W <==> B(HDF) 111-121 F11.4 --- eF555W e-correction HST F555W <==> V(YSC) 122-132 F11.4 --- eF569W e-correction HST F569W 133-143 F11.4 --- eF606W e-correction HST F606W <==> V(HDF) 144-154 F11.4 --- eF622W e-correction HST F622W 155-165 F11.4 --- eF675W e-correction HST F675W 166-176 F11.4 --- eF702W e-correction HST F702W 177-187 F11.4 --- eF791W e-correction HST F791W 188-198 F11.4 --- eF814W e-correction HST F814W <==> I(HDF) 199-204 F6.2 --- z redshift -------------------------------------------------------------------------------- Byte-by-byte Description of file: ek_in_l_xx.dat (fourth block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-12 F12.4 --- ku k-correction for Johnson U 13-24 F12.4 --- kb k-correction for Johnson B 25-36 F12.4 --- kv k-correction for Johnson V 37-48 F12.4 --- kr k-correction for Johnson R 49-60 F12.4 --- ki k-correction for Johnson I 61-72 F12.4 --- kj k-correction for Johnson J 72-84 F12.4 --- kh k-correction for Johnson H 85-94 F12.4 --- kk k-correction for Johnson K 95-102 F8.2 --- z redshift -------------------------------------------------------------------------------- Byte-by-byte Description of file: ek_in_l_xx.dat (fifth block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-12 F12.4 --- kku k-correction for Koo u 13-24 F12.4 --- kkb k-correction for Koo j 25-36 F12.4 --- kkv k-correction for Koo f 37-48 F12.4 --- kkr k-correction for Koo n 49-60 F12.4 --- kgi k-correction for Thuan & gunn g 61-72 F12.4 --- kgj k-correction for Thuan & gunn r 73-80 F8.2 --- z redshift -------------------------------------------------------------------------------- Byte-by-byte Description of file: ek_in_l_xx.dat (sixth block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-11 F11.4 --- kF160BW k-correction HST F160BW 12-22 F11.4 --- kF170W k-correction HST F170W 23-33 F11.4 --- kF185W k-correction HST F185W 34-44 F11.4 --- kF218W k-correction HST F218W 45-55 F11.4 --- kF255W k-correction HST F255W 56-66 F11.4 --- kF300W k-correction HST F300W <==> U(HDF) 67-77 F11.4 --- kF336W k-correction HST F336W 78-88 F11.4 --- kF380W k-correction HST F380W 89-99 F11.4 --- kF439W k-correction HST F439W 100-110 F11.4 --- kF450W k-correction HST F450W <==> B(HDF) 111-121 F11.4 --- kF555W k-correction HST F555W <==> V(YSC) 122-132 F11.4 --- kF569W k-correction HST F569W 133-143 F11.4 --- kF606W k-correction HST F606W <==> V(HDF) 144-154 F11.4 --- kF622W k-correction HST F622W 155-165 F11.4 --- kF675W k-correction HST F675W 166-176 F11.4 --- kF702W k-correction HST F702W 177-187 F11.4 --- kF791W k-correction HST F791W 188-198 F11.4 --- kF814W k-correction HST F814W <==> I(HDF) 199-204 F6.2 --- z redshift -------------------------------------------------------------------------------- Byte-by-byte Description of file: ek_in_l_xx.dat (seventh block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-12 F12.4 --- kau k-corr. with attenuation for Johnson U 13-24 F12.4 --- kab k-corr. with attenuation for Johnson B 25-36 F12.4 --- kav k-corr. with attenuation for Johnson V 37-48 F12.4 --- kar k-corr. with attenuation for Johnson R 49-60 F12.4 --- kai k-corr. with attenuation for Johnson I 61-72 F12.4 --- kaj k-corr. with attenuation for Johnson J 72-84 F12.4 --- kah k-corr. with attenuation for Johnson H 85-94 F12.4 --- kak k-corr. with attenuation for Johnson K 95-102 F8.2 --- z redshift -------------------------------------------------------------------------------- Byte-by-byte Description of file: ek_in_l_xx.dat (eighth block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-12 F12.4 --- kaku k-corr. with attenuation for Koo u 13-24 F12.4 --- kakb k-corr. with attenuation for Koo j 25-36 F12.4 --- kakv k-corr. with attenuation for Koo f 37-48 F12.4 --- kakr k-corr. with attenuation for Koo n 49-60 F12.4 --- kagi k-corr. with attenuation for Thuan & gunn g 61-72 F12.4 --- kagj k-corr. with attenuation for Thuan & gunn r 73-80 F8.2 --- z redshift -------------------------------------------------------------------------------- Byte-by-byte Description of file: ek_in_l_xx.dat (ninth block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-11 F11.4 --- kaF160BW k-corr. with attenuation HST F160BW 12-22 F11.4 --- kaF170W k-corr. with attenuation HST F170W 23-33 F11.4 --- kaF185W k-corr. with attenuation HST F185W 34-44 F11.4 --- kaF218W k-corr. with attenuation HST F218W 45-55 F11.4 --- kaF255W k-corr. with attenuation HST F255W 56-66 F11.4 --- kaF300W k-corr. with attenuation HST F300W 67-77 F11.4 --- kaF336W k-corr. with attenuation HST F336W 78-88 F11.4 --- kaF380W k-corr. with attenuation HST F380W 89-99 F11.4 --- kaF439W k-corr. with attenuation HST F439W 100-110 F11.4 --- kaF450W k-corr. with attenuation HST F450W 111-121 F11.4 --- kaF555W k-corr. with attenuation HST F555W 122-132 F11.4 --- kaF569W k-corr. with attenuation HST F569W 133-143 F11.4 --- kaF606W k-corr. with attenuation HST F606W 144-154 F11.4 --- kaF622W k-corr. with attenuation HST F622W 155-165 F11.4 --- kaF675W k-corr. with attenuation HST F675W 166-176 F11.4 --- kaF702W k-corr. with attenuation HST F702W 177-187 F11.4 --- kaF791W k-corr. with attenuation HST F791W 188-198 F11.4 --- kaF814W k-corr. with attenuation HST F814W 199-204 F6.2 --- z redshift -------------------------------------------------------------------------------- Byte-by-byte Description of file: colors.dat (first block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-06 I6 --- J Index 09-19 E13.5 y age age of system 21-28 F9.3 --- U Johnson U 29-37 F9.3 --- B Johnson B 38-46 F9.3 --- V Johnson V 47-55 F9.3 --- R Johnson R 56-64 F9.3 --- I Johnson I 65-73 F9.3 --- J Johnson J 74-82 F9.3 --- H Johnson H 83-91 F9.3 --- K Johnson K 92-100 F9.3 --- L Johnson L -------------------------------------------------------------------------------- Byte-by-byte Description of file: colors.dat (second block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-06 I6 --- J Index 09-19 E13.5 y age age of system 21-28 F9.3 --- u Koo u 29-37 F9.3 --- j Koo j 38-46 F9.3 --- f Koo f 47-55 F9.3 --- n Koo n 56-64 F9.3 --- g Thuan & Gunn g 65-73 F9.3 --- r Thuan & Gunn r -------------------------------------------------------------------------------- Byte-by-byte Description of file: colors.dat (third block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-06 I6 --- J Index 09-19 E13.5 y age age of system 20-27 F8.3 --- U-B Johnson U-B 28-35 F8.3 --- B-V Johnson B-V 36-43 F8.3 --- U-V Johnson U-V 44-51 F8.3 --- V-R Johnson V-R 52-59 F8.3 --- R-I Johnson R-I 60-67 F8.3 --- V-K Johnson V-K 68-75 F8.3 --- I-K Johnson I-K 76-83 F8.3 --- B-R Johnson B-R 84-91 F8.3 --- B-H Johnson B-H 92-99 F8.3 --- J-H Johnson J-H 100-107 F8.3 --- H-K Johnson H-K -------------------------------------------------------------------------------- Byte-by-byte Description of file: colors.dat (fourth block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-06 I6 --- J Index 09-19 E13.5 y age age of system 20-29 F10.3 --- C washington C 30-39 F10.3 --- M washington M 40-49 F10.3 --- T1 washington T1 50-59 F10.3 --- T2 washington T2 -------------------------------------------------------------------------------- Byte-by-byte Description of file: colors.dat (fifth block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-06 I6 --- J Index 09-19 E13.5 y age age of system 20-29 F10.3 --- u stroemgren u 30-39 F10.3 --- v stroemgren v 40-49 F10.3 --- b stroemgren b 50-59 F10.3 --- y stroemgren y -------------------------------------------------------------------------------- Byte-by-byte Description of file: colors.dat (sixth block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-06 I6 --- J Index 09-19 E13.5 y age age of system 20-30 F11.4 --- F160BW HST F160BW 31-41 F11.4 --- F170W HST F170W 42-52 F11.4 --- F185W HST F185W 53-63 F11.4 --- F218W HST F218W 64-74 F11.4 --- F255W HST F255W 75-85 F11.4 --- F300W HST F300W <==> U(HDF) 86-96 F11.4 --- F336W HST F336W 97-107 F11.4 --- F380W HST F380W 108-118 F11.4 --- F439W HST F439W 119-129 F11.4 --- F450W HST F450W <==> B(HDF) 130-140 F11.4 --- F555W HST F555W <==> V(YSC) 141-151 F11.4 --- F569W HST F569W 152-162 F11.4 --- F606W HST F606W <==> V(HDF) 163-173 F11.4 --- F622W HST F622W 174-184 F11.4 --- F675W HST F675W 185-195 F11.4 --- F702W HST F702W 196-206 F11.4 --- F791W HST F791W 207-217 F11.4 --- F814W HST F814W <==> I(HDF) -------------------------------------------------------------------------------- Byte-by-byte Description of file: galspec.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-06 I6 --- J Index 07-17 F11.1 A lambd wavelength xx-xx pe12.4 erg/cm^2/s/A flux Flux per wavelength. -------------------------------------------------------------------------------- Note (1): the age of the spectra can be found in the second line on top of each column. Because of 100 spectra there are 102 colums in this file. -------------------------------------------------------------------------------- Byte-by-byte Description of file: plotsgal.dat (first block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-13 E13.5 y age actual age. 14-27 E14.5 M_sun mt total mass of system 28-40 E13.5 M_sun ms total mass of stars in system 41-53 E13.5 M_sun mg total mass of gas in system 54-62 F9.5 --- -- ? 63-71 F9.5 --- -- metallicity Z (0 for SSPs) 72-84 E13.3 M_sun/y psip star formation rate 85-95 E11.3 --- -- ? 96-106 E11.3 --- ezj ejectionrate (0 for SSPs) -------------------------------------------------------------------------------- Byte-by-byte Description of file: plotsgal.dat (second block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-13 E13.5 y age actual age. 14-24 F11.4 --- m_bol bolometric magnitude 25-33 F9.4 --- m_u Johnson U 34-42 F9.4 --- m_b Johnson B 43-51 F9.4 --- m_v Johnson V 52-60 F9.4 --- m_r Johnson R 61-69 F9.4 --- m_i Johnson I 70-78 F9.4 --- m_j Johnson J 79-87 F9.4 --- m_h Johnson H 88-96 F9.4 --- m_k Johnson K 97-105 F9.4 --- m_l Johnson L (not included in the isochrones) -------------------------------------------------------------------------------- Byte-by-byte Description of file: plotsgal.dat (third block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-13 E13.5 y age actual age. 14-24 F11.4 --- U-B Color U-B 25-33 F9.4 --- B-V Color B-V 34-42 F9.4 --- V-R Color V-R 43-51 F9.4 --- R-I Color R-I 52-60 F9.4 --- I-J Color I-J 61-69 F9.4 --- J-H Color J-H 70-78 F9.4 --- H-K Color H-K 79-87 F9.4 --- L-J Color L-J (not included) 88-96 F9.4 --- U-V Color U-V 97-105 F9.4 --- V-K Color V-K -------------------------------------------------------------------------------- Byte-by-byte Description of file: plotsgal.dat (fourth block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-13 E13.5 y age actual age. 14-26 E13.5 --- l_bol bolometric luminosity 27-38 E12.5 --- l_u luminosity in U 38-50 E12.5 --- l_b luminosity in B 51-62 E12.5 --- l_v luminosity in V 63-74 E12.5 --- l_r luminosity in R 75-86 E12.5 --- l_i luminosity in I 87-98 E12.5 --- l_j luminosity in J 99-110 E12.5 --- l_h luminosity in H 111-122 E12.5 --- l_k luminosity in k 123-134 E12.5 --- l_l luminosity in L (not included) 135-145 E11.3 --- l_k lyman-continuum-photons (not calculated) -------------------------------------------------------------------------------- Byte-by-byte Description of file: bt.dat (first block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-05 I5 --- J Index 06-17 E12.3 y age actual age 18-25 F8.4 --- bt_u B/T in U (HST) without cosmology 26-33 F8.4 --- bt_b B/T in B (HST) 34-41 F8.4 --- bt_v B/T in V (HST) 41-49 F8.4 --- bt_i B/T in I (HST) 50-57 F8.4 --- bt_h B/T in H (Johnson) -------------------------------------------------------------------------------- Byte-by-byte Description of file: bt.dat (second block) -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 01-07 F7.3 --- z redshift 08-12 I5 --- J Index 13-24 E12.3 y age actual age 25-32 F8.4 --- btc_u B/T in U (HST) with attenuation 33-40 F8.4 --- btc_b B/T in B (HST) with attenuation 41-48 F8.4 --- btc_v B/T in V (HST) with attenuation 49-56 F8.4 --- btc_i B/T in I (HST) with attenuation 57-64 F8.4 --- btc_h B/T in H (Johnson) with attenuation 65-73 F8.4 --- btn_u B/T in U (HST) 74-81 F8.4 --- btn_b B/T in B (HST) 82-89 F8.4 --- btn_v B/T in V (HST) 90-97 F8.4 --- btn_i B/T in I (HST) 98-105 F8.4 --- btn_h B/T in H (Johnson) -------------------------------------------------------------------------------- ================================================================================ (End) Jochen Schulz 21-oct-2002